#pragma once
#include <iostream>
#include<vector>
#include<functional>
using namespace std;
namespace mh
{
    template<class T>
    class less {
    public:
        bool operator()(const T& x, const T& y)const
        {
            return x < y;
        }
    };
    template<class T>
    class greater {
    public:
        bool operator()(const T& x, const T& y)const
        {
            return x > y;
        }
    };
    template <class T, class Container = vector<T>, class Compare = less<T>>
    class priority_queue
    {
    private:
        Container c;
        Compare comp;
        void adjust_up(size_t child)
        {
            size_t parent = (child - 1) / 2;
            while (child > 0)
            {
                if (comp(c[parent], c[child]))
                {
                    swap(c[parent], c[child]);
                    child = parent;
                    parent = (child - 1) / 2;
                }
                else
                {
                    break;
                }
            }
        }
        void adjust_down(size_t parent)
        {
            size_t child = parent * 2 + 1;
            while (child < c.size())
            {
                if (child + 1 < c.size() && comp(c[child], c[child + 1]))
                {
                    ++child;
                }
                if (comp(c[parent], c[child]))
                {
                    swap(c[parent], c[child]);
                    parent = child;
                    child = parent * 2 + 1;
                }
                else
                {
                    break;
                }
            }
        }
    public:
        priority_queue()
        {
        }
        template <class InputIterator>
        priority_queue(InputIterator first, InputIterator last)
            :c(first, last)
        {
            for (size_t i = (c.size() - 1 - 1) / 2; i > 0; --i)
            {
                adjust_down(i);
            }
        }
        bool empty() const
        {
            return c.empty();
        }
        size_t size() const
        {
            return c.size();
        }
        const T& top()const 
        {
            return c.front();
        }
        void push(const T& x)
        {
            c.push_back(x);
            adjust_up(c.size() - 1);
        }
        void pop()
        {
            swap(c[0], c[c.size() - 1]);
            c.pop_back();
            adjust_down(0);
        }
    };
};